If you have Python4Suite installed in your system, it is possible to save XML documents as pages. It's important to start those pages with an XML declaration "<?xml ...>" in the very first line. Also, you have to specify the stylesheet that is to be used to process the XML document to HTML. This is done using a standard "xml-stylesheet" processing instruction, with the name of a page containing the stylesheet as the "href" parameter.
Do no forget to enable XSLT processing, see HelpOnConfiguration.
See the following example for details, which can also be found on the XsltVersion page.
Example
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="XsltVersion" type="text/xml"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" omit-xml-declaration="yes" indent="no"/>
<xsl:template match="/">
This Wiki is running an XSLT engine by
<xsl:value-of select="system-property('xsl:vendor')"/>
(<a href="{system-property('xsl:vendor-url')}"><xsl:value-of select="system-property('xsl:vendor-url')"/></a>)
implementing XSLT v<xsl:value-of select="system-property('xsl:version')"/>
</xsl:template>
</xsl:stylesheet>